1. Field of the Invention
The present invention relates to a sheet punching device for cutting a hole in a sheet, and to an image forming apparatus, such as a copying machine, a facsimile machine, a printer and a composite equipment of those devices, provided with the sheet punching device.
2. Related Background Art
Up to now, a sheet punching device is designed such that punch debris produced when a hole is cut in a sheet by a punch and a die is permitted to naturally drop into a punch debris box disposed just under the sheet punching device.
For that reason, when the punch debris box is detached from a main body of the sheet punching device in order to dispose of the punch debris collected within the punch debris box, there is a case in which the punch debris which is left adhered to the punch or the die and remains there drops down and is scattered to the surroundings to leave rubbish.
Also, since the punch debris is liable to be electrostatically charged, there is a case in which the punch debris is adhered to a punch debris discharge port of the sheet punching device and massed so as not to surely drop into the punch debris box, whereby the discharge port is jammed with the punch debris.
Further, because the punch debris drops down at the same position within the punch debris box and is concentrated at one location so as to heap up into a mountain shape (a conical shape), unless the punch debris box is vibrated by a vibrator so that the punch debris is leveled, the space within the punch debris box cannot be effectively used. As a result, the structure becomes complicated, and the vibrating sound of the vibrator constitutes a noise factor.
In addition, in the image forming apparatus having the conventional sheet punching device, since the punch debris box is disposed within the main body of the image forming apparatus, the main body must be opened and closed when the punch debris is disposed of. However, because the image forming apparatus automatically stops to operate when opening the main body, the operating efficiency of the image forming apparatus is degraded. Also in closing the main body, because the image forming apparatus becomes operative after a given period of time elapses, the operating eff iciency of the image forming apparatus is de graded as much.
The present invention has been made to solve the above problems, and therefore an object of the present invention is to provide a sheet punching device that can readily conduct a disposal of punch debris, and an image forming apparatus having the sheet punching device.
In order to achieve the above object, according to the present invention, there is provided a sheet punching device comprising: a punch and a die, which cut a hole in a sheet; punch debris conveying means for conveying punch debris produced when the punch and the die cut a hole in the sheet; and a punch debris box for receiving the punch debris which has been conveyed by the punch debris conveying means, wherein the punch debris box is disposed at an end portion in a direction intersecting a sheet conveying direction, and the punch debris conveying means conveys the punch debris in a direction intersecting the sheet conveying direction to the punch debris box.
In the sheet punching device according to the present invention, the punch debris conveying means comprises a screw received in a casing positioned above the punch debris box, and an opening portion through which the punch debris passes is defined in a portion where the punch debris box and the casing are opposed to each other.
In the sheet punching device according to the present invention, punch debris forcibly dropping means for forcibly dropping the punch debris from the opening portion of the casing to the opening portion of the punch debris box is disposed on a portion opposed to the opening portion of the casing for the screw.
In the sheet punching device according to the present invention, the punch debris forcibly dropping means comprises a vane.
In the sheet punching device according to the present invention, a plurality of protrusions are formed on an inner wall of the opening portion of the casing.
In the sheet punching device according to the present invention, the punch debris box includes punch debris dispersing means for dispersing the punch debris by utilizing the drop of the punch debris that drops into the punch debris box.
In the sheet punching device according to the present invention, the dispersing means comprises a dispersing member of punch debris formed into an angled shape.
In the sheet punching device according to the present invention, the punch and the die are actuated by punch/die driving means that continues the actuation even if the punch debris box is detached from the main body, and the punch debris conveying means is actuated by conveyance driving means that stops the actuation when the punch debris box is detached from the main body.
According to the present invention, there is provided an image forming apparatus comprising:
sheet stacking means on which sheets are stacked;
image forming means for forming an image on the sheet supplied from the sheet stacking means; and
a sheet punching device defined in any one of the above structures, in which
the image forming apparatus further comprises a punch debris box of the sheet punching device detachably attached onto an outer side of the main body, and image forming control means for continuing the operation of the image forming means even if the punch debris box is detached from the main body.
In the sheet punching device according to the present invention, because the punch debris produced when a hole is cut in a sheet by the punch and the die is conveyed to the punch debris box by the punch debris conveying means, it is easy to dispose of the punch debris within the punch debris box. Specifically, the punch debris box can be arranged at an easily detachable position to improve the operability. Also, even if the punch debris left stuck onto the punch and the die drops down when the punch debris box is detached, because the punch debris is received by the punch debris conveying means, the punch debris can be prevented from being scattered to the outside of the device as rubbish.
In the sheet punching device according to the present invention, when the punch debris with static electricity is going to be attracted to the opening portion of the casing, the punch debris is forcibly dropped into the punch debris box by the punch debris forcibly dropping means, to thereby prevent the punch debris from being massed and attracted to the opening portion, and prevent jamming caused by the punch debris. The present invention is thus capable of smoothly dropping down the punch debris into the punch debris box.
In the sheet punching device according to the present invention, since a plurality of projections are formed on the inner wall of the opening portion, when the punch debris with static electricity is going to be attracted to the opening portion of the casing, it is difficult to attract the punch debris to the inner wall of the opening portion, and the punch debris is prevented from being massed and attracted to the opening portion to prevent jamming caused by the punch debris. The present invention is thus capable of smoothly dropping the punch debris into the punch debris box.
In the sheet punching device according to the present invention, since there is provided the punch debris dispersing means for dispersing the punch debris by utilizing the drop of the punch debris, the punch debris is uniformly collected within the punch debris box without being concentrated on one place, no vibrator as required in the conventional device is necessary. The present invention is thus capable of making the structure simple and eliminating vibrating noises.
In the sheet punching device according to the present invention, the punch and the die are actuated by punch/die driving means that continues the actuation even if the punch debris box is detached from the main body, and the punch debris conveying means is actuated by the conveyance driving means that stops the actuation when the punch debris box is detached from the main body. With the above structure, the punch debris can be prevented from scattering by the punch debris conveying means when the punch debris box is detached regardless of such a situation that the punching operation is continued.
In the image forming apparatus according to the present invention, the punch debris box of the sheet punching device is detachably attached to the outer side of the main body, and if the punch debris box is detached from the main body, the image formation of the image forming means is continued by the image forming control means to thereby, unlike the conventional devices, continue the image forming operation by the image forming means. The present invention is thus capable of enhancing the productivity of the image formation.